Ash hopper



Oct. 11, 1960 E. B. TOLMAN 2,955,878

ASH HOPPER Filed April 16. 195s 2,955,818 Asn HOPPER Edgar B. Tolman, Winnetka, Ill., to United Con- This invention relates to lan ash hopper, VVandV lin particular it relates to a hopper constructionr'which 'may receive fly ash from a furnace and feed it into a vacuum conveyor system.

The huge quantities of very line ash which are produced in a modern power plant coal burning boiler 'present serious handling problems. VThe materialzjisuinherently difficult to store and transport, because it ishsg fi that it packs almost into a solid mass in a hopper s orag'e vessel, and even ow of the ash is difficult to achieve b'ecauseV of the way it will arch, slump, and otherwisebehave in a manner inimical to easy handling. p y

One of the most diicult pieces of equ'pnient which to obtain satisfactory. ash owis a standard fhopper bottom, such as is found in a centrifugal separator or el'ectrostatic precipitator, which has a tapered lilottmpoir-y tion terminating in an outfeed opening. A sthehhopper lls, the weight of ash packs the discharge opening-and forms a solid mass between the converging walls of the lower portion of Vthe hopper. lf the hopper is provided with a conventional discharge gate, the opening of the gate may permit a small drop of ash from the area immediately above the hopper dischargenopening; butthe majority of material in the hopper will remain packed between the converging side walls. l l

In accordance with the presentinvention, the hopper is provided with generally 'horizontallydisposed a" ating devices of conventional construction which are positioned a substantial distance above the bottom of the tapered portion of the hopper. These aerating elements provide supporting shelves which prevent the weight of the ash above from packing the ash in the lower part of the hopper between the converging side walls. Each aerating element is provided with a source of low pressure air in the usual fashion, and this aerating air fluidizes the ash so that it may ow freely down through the hopper and out the bottom discharge opening.

Secured to the bottom of the hopper, to receive ash through the discharge opening, is an aerating chamber which has an inclined aerating floor and a discharge orifice of relatively small size the lower side of which is flush with the lower end of the aerating oor.

Discharge of ash from the hopper may occur in a smooth, even flow, without arching or slumping of the ash in the hopper, and with no packing of ash between the converging side walls of the lower portion of the hopper.

When a sucient amount of ash has lbeen released from the hopper the flow of aerating air may be stopped; and this will stop the feed of ash out of the hopper so that the vacuum conveyor conduit into which the hopper feeds the ash may receive ash from another hopper or hoppers in a large system.

The invention is illustrated in a preferred and an alternative embodiment in the accompanying drawings in which:

Fig. l is a vertical central sectional View of the preferred embodiment of the invention;

Died Staten-Paesi "ice 2 Fig. 2 is a section taken substantially as illustrated alongthelineZ-ZofFig 1'; Fig. 3 is a vertical central sectional view 'of "an alternative embodiment of vthe invention;

Fig. 4 is a section taken substantially a's illustrated along the line 4 4 o fFig.3, Referring to the drawings in greater detail, and referring first to Figs. l and 2, the lowerpart 9 of an collecting device has a continuous, upright wall portion 1 0 which merges at its lower end into a frustopyragmidal bottom portion, indicated generally at 1 1, th'ejconvergili'g Walls ofwhich are numbered, 12, 13, afnd'l A t the bottom of the hopper body 'is an outfeed o of relatively small width and area. Extending 'd 1y from the hopper body ,beneath openingfls is feed throat 17 communicating with anaeratin'gpham er, indicated generally at 1 8.Y Aeratingchamberls is' pro. vided with an aeratingoor ;19.whic h is. pitched 'to4 an upright partition Z0 in which 'tlierejis discharge orifice 21 by means of which aerating chamber jcpmmriicats with Va discharge throat 2 2 jleadingto v aic' conduit (not shown). Aeratingo'or n al porous construction, so thatair 'entering a plenum chamber 23 below the aerating o'or from alovy.pres-` surejair line 24 may ditu se t hroug l1 the door 19 and aerat'e, or iluidize ashginfaerating 'cha'b 1 8'. several'hoppers like the hopper here disclosedar'eor ily used to feeda singlevauurn cpnveyonconduit l aerating Chambers prvided 'with a shut stivali/feanism 25 for closing the discharge orifice 21 when the hopper9isempty, j. v.

The aerating chamber 1S 'aioids 'shiooth'oiv of fl ized ash Which has passed through the Giltfd jo` m. i 16 ofthe hopper; but 'the A' frusto-pyramidal bottom portignfof the hfo -diculty in the f e'ed. of ash through the r'ela stricted outfeed opening 1'6 In present invention",thefrustofpyram of thelhopperis provided with aerating generally at 26, which .iricliic`l`e-sC 'a A Zontalaerating shelve'sjd2?, "d ylfrom the side walls iz and/13, respectively; fthe hopper-why, a substantial distance above outfeed opening 16. The aerating shelves 27 and 28 act as supports for ash in the hopper 9, to prevent it from packing between the c011- verging side Walls of the hopper, and since each of the shelves is an aerating element it may be used to fluidize the ash which is supported on it, so that the ash Hows freely toward the outfeed opening 16. As seen in Fig. 1, aerating shelf 27 is mounted above shelf 28, and the inner edges 27a and 28a of the shelves overlap so that ash may liow from shelf 27 onto shelf 28, and thence to outfeed opening 16.

Aerating air for the shelves 27 and 28 is provided, respectively, by air lines 29 and 30 which, together with line 24 for aerating oor 19, are fed from a single low pressure air line 31.

If desired, hopper 9 may be provided with a vertical baille 32 which extends transversely of aerating shelves 27 and 2S, in order to divide the ow of ash through the hopper.

Referring now to Figs. 3 and 4, the construction of the ash hopper 9 and the aerating chamber 18 are identical with the form of device just described, so that these components will not be described in detail; and their various elements are given reference numerals identical to those in the form just described.

In this form of device, the aerating means in the bottom portion 11 of the hopper is indicated generally at 126, and includes generally horizontal, coplanar aerating shelves 127 and 128 which extend inwardly from the side walls 12 and 13, respectively, of the hopper body, a substantial distance above outfeed opening 16. The aerating'shelve's 127 and 128 act as supports for ash in the hopper 9, to prevent it from packing between the converging side walls of the hopper, and since each of the yshelves is an aerating element it may be usedto iluidize the ash vvvliieh'is supported onvit, so that the ash flows freely towardthe outfeed Yopening 16. AsV seen in'Eig.' 3, theV innerA edges 127aY and `128a of the'aerating' shelves `127 and 128 are spaced apart to provide an'opening 133 which is directly above outfeed opening 16. In 'the illus- Vtrated embodiment, the space betweenthe shelves is narrow'er than the outfeed opening 16; but it is obvious that the only limit onthe width of the space 133 is that it shall not be substantially wider thanroutfeed opening 16, so that the aerating shelves V127Y and 128 may occupy a major part of vthe Width of the hopper. Y t. Aerating air'for the/shelves 127 and 128 is provided, respectively, by air lines 129 and 130 which,'together with 4a line 24 for the aerating oor 19 of the aerating chamber 18, are fed from a single low pressure airline 31. If desired, hopper 9 may be provided with a vertical baihe132 which extends transversely across the two aerating-shelves 127 and 128, in order to divide the flow of ash Vthrough the hopper. Y The foregoing detailed description is given for clear- -ness of understanding only and no unnecessary limitations `are'to .be understood therefrom, as modifications will be obvious to those skilled in the art.

I claim: p l

1. An ash hopper comprising: a hopper body which tapers toward its lower end and `has a bottom outfeed opening of relatively small width and area; upper aerating means including a plurality of generally horizontal aerating shelves extending inwardly from the sides of the hopper body a substantial distance above said outfeed opening to support and uidize ash for free flow to and through said opening; an aerating chamber securedv to the' bottom of the hopper body to receive ash therefrom,Y

said chamber having a discharge oriiice at one end; and a. floor in said chamber provided with aerating means to uidize ash for free ow through the discharge orifice.

2. 'Ifhe device of claim 1 in which the aerating shelves are in a single plane with a space between the inner mar; gins of opposite shelves which is not substantially greater than the width of the outfeed opening.

3, The device of claim 1 in which the aerating shelves are on opposite sides of the hopper body and are vertical. ly spaced with their inner edges overlapping so that uidized ash may ow from one shelf to another.

4. An ash hopper comprising: a hopper body the upper portion of which has substantially vertical Walls, and the lower end portion of which has uninterrupted inclined walls converging to a bottom outfeed opening of relatively small width and area, said uninterrupted converging walls tending to compact ash adjacent the outfeed opening and thus inhibitits free flow through said opening; a plurality of generally horizontal shelves extending inwardly from said converging walls of the lower end of the hopper body a substantial distance above said outfeed opening, eachl of said shelves having its inner margin not substantially farther from the vertical axis of the hopper than a vertical plane through the adjacent margin of the outfeed opening, so that ash may ilow-oi the inner margin of each shelf into a space substantially directly above said opening, said shelves cooperating to support ashin the .hopper Yand 'minimize thecompacting effect of the unin.- ternlpted converging walls; aerating means on each shelf to uidize the ash above said shelf and thereby. promote free ow of ash from all said shelves to and through the outfeed opening; an aerating chamber secured to the bot- 6. Ihe device Vof claim 4 in which there are two co- Y planar shelves on opposite sides ofthe hopper body, and the `distance between their inner margins is not substantially greater than the width ofthe outfeed opening.

References Cited in the le of this patent f Y YUNITED STATES PATENTS 2,125,913 Goebels Aug. 9, 1938 2,316,814 Schemm Apr. 20, 1943 2,734,782, Galle Feb. r14, 1956 2,746,807 Tolman May 22, 1956 2,776,171 Mylting Ian. l, 1957 2,883,240

Hahl Apr. 21, 1959 

